Organizations such as on-line retailers, Internet service providers, search providers, financial institutions, universities, and other computing-intensive organizations often conduct computer operations from large scale computing facilities. Such computing facilities house and accommodate a large amount of server, network, and computer equipment to process, store, and exchange data as needed to carry out an organization's operations. Typically, a computer room of a computing facility includes many server racks. Each server rack, in turn, includes many servers and associated computer equipment.
Because the computer room of a computing facility may contain a large number of servers, a large amount of electrical power may be required to operate the facility. In addition, the electrical power is distributed to a large number of locations spread throughout the computer room (e.g., many racks spaced from one another, and many servers in each rack). Usually, a facility receives a power feed at a relatively high voltage. This power feed is stepped down to a lower voltage. A network of cabling, bus bars, power connectors, and power distribution units, is used to deliver the power at the lower voltage to numerous specific components in the facility.
Some data centers include back-up components and systems to provide back-up power to servers in the event of a failure of components or systems in a primary power system. In some data centers, each primary power system may have its own back-up system that is fully redundant at all levels of the power system. For example, in a data center having multiple server rooms, each server room may have its own primary power system and back-up power system. The back-up system for each server room may have a switchboard, uninterruptible power supply, and floor power distribution unit (PDU) that mirrors a corresponding switchboard, uninterruptible power supply, and floor power distribution unit in the primary power system for that server room. Providing full redundancy of the primary power systems may, however, be very costly both in terms of capital costs (in that in may require a large number of expensive switchboard, uninterruptible power supplies, and PDUs, for example) and in terms of costs of operation and maintenance.
Some data centers with an uninterruptible power supply in a primary power system or back-up power system may have a large affected zone when an uninterruptible power supply failure in the primary or back-up power system occurs. In addition, some data centers have “single threaded” distribution via the electrical supply to the floor, and in which maintenance can only be performed when the components are shut-off.
Some data centers with primary power systems and back-up power systems include automatic transfer switches to switch between the primary and back-up power systems in case of a loss of power in one of the power systems. Such, automatic transfer switches may include mechanical components, such as a mechanical switches, that require periodic testing and maintenance, thus adding to costs of operation of the data center. Also, some mechanical automatic transfer switches may fail to switch or may be delayed in switching during a loss of power event thus adversely affecting operation of computer systems receiving electrical power via the automatic transfer switch.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The headings used herein are for organizational purposes only and are not meant to be used to limit the scope of the description or the claims. As used throughout this application, the word “may” is used in a permissive sense (i.e., meaning having the potential to), rather than the mandatory sense (i.e., meaning must). Similarly, the words “include,” “including,” and “includes” mean including, but not limited to.